Studies On The Low-temperature Drying Technology And Floating Period Of Bacillus Sphaericus

Bacillus sphaericus (B.s) is a strictly aerobic microorganisms. It exists widely in the nature, especially in the soil and water area. B.s is very toxic to the mosquito larvae, but it is thermosensitive and easy to deposit in water. And these unique characteristics confine its value of the actual use in industrial production. Therefor, the research of low-temperature production processes and new forms of B.s products is attractive.Based on membrane separation technology which has been utilized widely in the past ten years, this paper shows a new production process of B.s products. With this new technology, the ratio of the collected active component increases to 91.8%, 12.78% more than that with the way of the traditional dusting process. In addition, the corn-cob is used as carrier of B.s. The formulation and processing technology of B.s are preliminary studied. According to this study, the potency of the products is as much as 3500ITU/mg. In the test of efficacy against 3rd and 4rd instar Cules pipiens quinque facciatus larvae, after using a preparation of potency 3500ITU/mg(4mg/L) within 42 days, the ratio of the mosquito living is below 30%.